/**
 * Unified Sub-nav Component — 4page-ui-unification Phase 0
 * 설계 섹션 4-C 전체 반영
 * 스코프: .page-* 만 활성. Phase 1+ 스킨 body에 .page-{slug} 추가 시 활성화.
 */

.page-prep .sub-nav,
.page-tc .sub-nav,
.page-bd .sub-nav,
.page-hs .sub-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--white);
  border-bottom: 1px solid var(--ink-300);
  box-shadow: var(--shadow-sm);
}

.page-prep .sub-nav-list,
.page-tc .sub-nav-list,
.page-bd .sub-nav-list,
.page-hs .sub-nav-list {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  padding: var(--space-3) 0;
  margin: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.page-prep .sub-nav-list::-webkit-scrollbar,
.page-tc .sub-nav-list::-webkit-scrollbar,
.page-bd .sub-nav-list::-webkit-scrollbar,
.page-hs .sub-nav-list::-webkit-scrollbar {
  display: none;
}

.page-prep .sub-nav-chip,
.page-tc .sub-nav-chip,
.page-bd .sub-nav-chip,
.page-hs .sub-nav-chip {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 999px;
  background: var(--ink-100);
  color: var(--ink-700);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  text-decoration: none;
  transition: all 0.15s ease;
}

.page-prep .sub-nav-chip:hover,
.page-tc .sub-nav-chip:hover,
.page-bd .sub-nav-chip:hover,
.page-hs .sub-nav-chip:hover {
  background: var(--page-accent-soft);
  color: var(--page-accent);
}

.page-prep .sub-nav-chip.is-active,
.page-tc .sub-nav-chip.is-active,
.page-bd .sub-nav-chip.is-active,
.page-hs .sub-nav-chip.is-active {
  background: var(--page-accent);
  color: var(--white);
}

@media (max-width: 768px) {
  .page-prep .sub-nav-list,
  .page-tc .sub-nav-list,
  .page-bd .sub-nav-list,
  .page-hs .sub-nav-list {
    justify-content: flex-start;
    padding-left: var(--container-pad-mobile);
    padding-right: var(--container-pad-mobile);
  }
}